gms | German Medical Science

Objective: Trans- and extraforaminal disc herniations should be treated via a lateral approach, either trans muscular, paramedian or minimal invasive far lateral. This approach can be technically difficult because of joint instability, spondylarthrosis and the importance of adjacent osseous structures, swelling of the spinal ganglia and proximity of the radicular vessels. This technique seems to be very effective and shows a low complication rate. For the cases of symptom recurrence extended foraminotomy and fusion seems to be the best option.

Method: Retrospective analysis over the last 5 years of data of all patients in our service with herniated disc surgically treated with a lateral approach. We focused on those patients who needed reoperations following development of new low-grade back pain, lumbar radiculopathy and with neurological deficits. Of a total of 119 patients treated by far lateral approach 6 underwent revision and extended foraminotomy as well as fusion of the operated segment.

Results: The lateral approach is an effective therapy option with 6,7% rate of revision operation surgery. 5% required fusion on order to control the symptoms. From the total number of laterally operated patients one developed an abscess and one a late postoperative bleeding, both of them were operated but needed no fusion. The other 6 cases reported low back pain and neurological deficits due to L4 nerve compression. In all the revision cases the affected segment was L4/5, in three cases on the right side. The MRI showed a foraminal stenosis in all cases. In 2 of the 6 cases a conventional osseous decompression was initially attempted with little benefit. Finally all 6 patients received lumbar fusion of the preoperated segment. The fusion techniques were variable. The median time for reoperation was 7 months with a range between 1 month and 3 years. After undergoing fusion all patients showed neurologic improvement and reported durable relief of pain.

Conclusions: Although the recurrence of radicular symptoms after lateral decompression is low, the few cases that develop recurrent stenosis of the foramen need segmenteal distraction and fusion. An accurate diagnosis for joint instability should be introduced in the pre-operative diagnostic protocol when a lateral approach is considered. When joint instability is present the lateral approach for disc herniation should be reconsidered: distraction and fusion are thought to be a better technique in order to avoid chronic radiculopathy due to L4 compression.